Little less info, but if you call support the following will problably asked / told to you:
downgrade to SP2, this is the officially supported SP for Win2K (See release notes)
What type of card and drivers are you using?
I don't think it has anything to do with IE6 or WM, this looks more like a driver or physical problem. If you have the possibility make a trace with another Sniffer to see what is happening on the ring.
Robert
Robert A.H. Wullems
Sniffer University Instructor
SCM / CNX / MCP
Citee Education
the Netherlands